The Horizontal-to-Vertical spectral ratio method (or H/V ratio method) is an empirical method that is based on the computation of the ratio of vertical ambient noise ground motion over horizontal ambient noise ground motion as a function of frequency. It provides an accurate fundamental frequency and minimum site amplification factor and thus is used in Engineering Seismology to determine site response.
The program that we use to determine spectral ratio is Geopsy and as input we use waveforms recorded with our Guralp seismometers. Several of the PCs in the Geology computer room, PCs 3-8, have the program installed.
Tutorial:
Geopsy Tutorial Tutorial that guides you on how to use Geopsy and gives you an idea of what the outcome should look like.
Program download link:
The newest updates for geopsy for all platforms no longer include libraries developed by outside authors, such as the geopsyhv library. I have been told by the development team that they hope to have a new version with geopsyhv by the end of this year. In the meantime, you have to install an older release, and make sure to select all for the download:
PCs in the student computer room and grad room should all have working versions of Geopsy installed.
On the department PCs, if the toolbar doesn't show up, go to Preferences > Tool. Under Search Path, add C:\Program Files (X86)\Geopsy.org\bin. Click "Ok", exit and restart Geopsy. This is a bug that exists only for some student accounts, not for others.
(this is just a small sample of papers that are available for free, by no means should these references be considered exhaustive, feel free to add good, free!, papers)
The program that we use to determine spectral ratio is Geopsy and as input we use waveforms recorded with our Guralp seismometers. Several of the PCs in the Geology computer room, PCs 3-8, have the program installed.
Tutorial:
Geopsy Tutorial Tutorial that guides you on how to use Geopsy and gives you an idea of what the outcome should look like.Program download link:
The newest updates for geopsy for all platforms no longer include libraries developed by outside authors, such as the geopsyhv library. I have been told by the development team that they hope to have a new version with geopsyhv by the end of this year. In the meantime, you have to install an older release, and make sure to select all for the download:PCs in the student computer room and grad room should all have working versions of Geopsy installed.
Guidelines for H/V ratio:
Guidelines for the Implementation of the H/V Spectral Ratio Technique on Ambient VibrationsThis document gives you general guidelines on how to determine whether your results indicate a reliable H/V Curve and/or a reliable H/V peak and how to interpret your results.
Some references
(this is just a small sample of papers that are available for free, by no means should these references be considered exhaustive, feel free to add good, free!, papers)